Survey on Various Techniques of User Authentication and Graphical Password

The process of identifying an individual usually based on a username and password. Passwords are the best commonly used method for identifying users in computer and communication systems. Usually, passwords are strings of letters and digits, i.e., they are alpha-numeric. Graphical passwords, which contain of some actions that the user accomplishes on an image. In this paper, the authors make a survey of the basic authentication and its techniques. Survey of various techniques for authentication and password security in a video CAPTCHA, persuasive cued click-points knowledge-based authentication mechanism.